Generally, a plurality of times of mask exposures is needed in a process of manufacturing a display substrate, and a mask plate with a certain pattern is needed when performing each mask exposure. In the related art, the mask plate is generally an open mask, which includes a bar-shaped or a groove-shaped mask opening. In a process of mask exposure, light passes through the mask opening and irradiates photoresist to pattern the photoresist.
The mask plate in the related art cannot provide a closed-loop shaped mask opening as shown in FIG. 1. When forming a closed-loop shaped pattern, a plurality of times of mask exposures is needed, and this greatly increases production cost and reduce production efficiency. In order to provide a mask with a closed-loop shaped opening, ribs (as shown in a dashed box in FIG. 2) are generally added in the mask plate in the related art. However, this mask plate has disadvantages such as unsatisfactory coating efficiency and unsatisfactory uniformity of a formed film at positions corresponding to ribs, thus an overall quality of the film formed on the substrate is severely affected.